The present invention relates to a tape carrier package, to which semiconductor pellets are bonded and which is used for such as a flexible printed circuit (FPC), in particular, in which a tape automated bonding (TAB) tape is used.
First, a first example of a conventional tape carrier package is explained. FIG. 1 is a plan view of the first example of the conventional tape carrier package. FIG. 2 is a sectional view at the C to Cxe2x80x2 section of FIG. 1. As shown in FIGS. 1 and 2, a conventional tape carrier package 50 provides plural conductive leads 53 on a base film 52 having a device hole 51 whose shape is rectangular. And inner leads 53a of the conductive leads 53 are formed in a state that the inner leads 53a stick out to the device hole 51. Furthermore, sprocket holes 54 are provided at the both edges side of the base film 52 in a state that the sprocket holes 54 have the same intervals.
A semiconductor pellet (die) 55 provides plural metal bumps 56, and each of the plural metal bumps 56 is bonded to a corresponding inner lead 53a of the conductive leads 53 by a heat press of a pressing tool (not shown).
Next, a second example of the conventional tape carrier package is explained. FIG. 3 is a sectional view of the second example of the conventional tape carrier package. In this, at the second example, equivalent elements to the first example shown in FIGS. 1 and 2 have the same reference numbers, and the same explanation is omitted. As shown in FIG. 3, a conventional tape carrier package 60 provides a base film 61 not having a device hole, and plural conductive leads 62 are provided on this base film 61. And a semiconductor pellet 55 provides plural metal bumps 56, and each of the plural metal bumps 56 is bonded to a corresponding inner lead 62a of the conductive leads 62 by a heat press of a pressing tool (not shown).
This second example is a tape carrier package used so called a face down bonding system. At this tape carrier package, the inner leads 62a are fixed to the base film 61, therefore this package has a characteristic that the inner leads 62a are not bent easily by external force. This example is disclosed in Japanese Patent Application Laid-Open No. HEI 5-251510.
Next, a third example of the conventional tape carrier package is explained. This third type example is disclosed in Japanese Patent Application Laid-Open No. HEI 3-85740 and Japanese Patent Application Laid-Open No. HEI 3-101140. FIG. 4 is a plan view of the third example of the conventional tape carrier package. FIG. 5 is a sectional view at the D to Dxe2x80x2 section of FIG. 4. In this, at the third example, equivalent elements to the first example shown in FIGS. 1 and 2 have the same reference numbers, and the same explanation omitted. As shown in FIGS. 4 and 5, a conventional tape carrier package 70 provides plural conductive leads 72 on a base film 52 having a device hole 71 whose shape is rectangular. And inner lead 72a of the conductive leads 72 are formed in a state that the inner leads 72a do not stick out to the device hole 71. Furthermore, sprocket holes 54 are provided at the both edge sides of the base film 52 in a state that the sprocket holes 54 have the same intervals.
And a semiconductor pellet 55 provides plural metal bumps 56, and each of the plural metal bumps 56 is bonded to a corresponding inner lead 72a of the conductive leads 72 by a heat press of a pressing tool (not shown).
And at least one or more slits 73 are provided at the base film 52 between adjacent conductive leads 72 at the near parts of the tip of the inner leads 72a of the conductive leads 72. By providing this kind of slits 73, a stress generated by the differences of thermal expansion coefficients and humidity expansion coefficients among a sealing resin material (not shown) using at bonding, the conductive leads 72, the base film 52, and the semiconductor pellet 55 can be absorbed. With these slits, defects caused by cracking of the resin material and braking of leads can be prevented.
However, at the tape carrier package 50 of the first example, the inner leads 53a float in the air, as a result, there is a problem that the inner leads 53a are easily bent by external force. In order to solve this problem, the tape carrier package 60 of the second example was developed. However, at this tape carrier package 60, the alignment between the semiconductor pellet 55 and the inner leads 62a is technically difficult, consequently, there is a problem that the yield is reduced. As the same as the second example, in order to solve the problem of the tape carrier package 50 of the first example, the tape carrier package 70 of the third example was also developed. However, at this tape carrier package 70, the base film 52 is deformed by the temperature at the bonding, as a result, there is a problem that non-intentional positions between the semiconductor pellet 55 and the conductive leads 72 may become short-circuit accidentally.
It is therefore an object of the present invention to provide a tape carrier package, in which inner leads are prevented from bending by external force, and the yield is made to improve, and non-intentional short-circuits between wiring on a base film and a semiconductor pellet caused by heat at bonding can be prevented.
According to the present invention, for achieving the objects mentioned above, there is provided a tape carrier package. Said tape carrier package provides a base film in which rectangular shaped first holes are provided, plural conductive leads, whose one ends are positioned not sticking out to each of said rectangular shaped first holes, on said base film, a second holes provided at the corner parts of each of said rectangular shaped first holes on said base film at the outside of each of said rectangular shaped first hole, and a semiconductor pellet in which plural metal bumps are provided. And said plural metal bumps are bonded to corresponding ends of said plural conductive leads.
According to the present invention, said conductive leads are provided on said base film in a state that said one ends of said conductive leads do not stick out to each of said rectangular shaped first holes, and said second holes are provided at the corner parts of each of said rectangular shaped first holes at the outside of each of said rectangular shaped first holes. With this structure, inner leads of said conductive leads are prevented from bending by external force, the yield is made to improve, and short-circuits at non-intentional positions between wiring on said base film and said semiconductor pellet caused by heat at bonding can be prevented.